Securely executing voice actions using contextual signals

ABSTRACT

In some implementations, (i) audio data representing a voice command spoken by a speaker and (ii) a speaker identification result indicating that the voice command was spoken by the speaker are obtained. A voice action is selected based at least on a transcription of the audio data. A service provider corresponding to the selected voice action is selected from among a plurality of different service providers. One or more input data types that the selected service provider uses to perform authentication for the selected voice action are identified. A request to perform the selected voice action and (i) one or more values that correspond to the identified one or more input data types are provided to the service provider.

FIELD

This specification describes technologies related to voice actions.

BACKGROUND

Voice activated devices may perform voice actions in response to speech.For example, a person may say “Computer, call 1-888-888-8888” and theirmobile computing device may, without further input from the person, callthe number 1-888-888-8888.

SUMMARY

Voice actions generally are intended to enable users to convenientlycause actions to be performed. For example, a user may simply say“Computer, set a timer for one minute” while they are cooking instead ofphysically interacting with a device to create a timer for one minute.However, some voice commands request voice actions that may have seriouseffects. For example, executing a voice action may disarm a homesecurity system, order items at a large monetary cost, or greatly changea home temperature setting. Additionally, devices that perform voiceactions may be accessible to multiple people. For example, a device thatperforms voice actions may be on a kitchen counter and may receivespeech from any person speaking near the device. Accordingly, applyingsecurity restrictions when executing voice actions may be important. Forexample, it may be desirable for a system to disarm a security system inresponse to a homeowner saying “Computer, disarm security system” andnot disarm the security system in response to a guest or an intrudersaying “Computer, disarm security system.”

Accordingly, to securely perform voice actions, a system may identify aspeaker from their voice and use additional contextual signals toauthenticate the speaker. Contextual signals may include, for example,an indication that a user's mobile computing device is home, anindication that the user's mobile computing device has been on aperson's body since it was last unlocked, or some other signal. Forexample, the system may receive an utterance of “Computer, disarmsecurity system,” identify the speaker's voice as that of the homeowner,and in response, further determine that the home owner's mobilecomputing device is in the home. The command to disarm the securitysystem can be performed based on the successful voice identification andthe physical presence of the computing device. By contrast, the systemcan be configured so that if required contextual factors are notpresent, e.g., if voice identification failed or if the homeownerscomputing device were not present in the home, then the command would bedisallowed for failing to meet security requirements. As a result, thesystem may improve the security of execution of voice actions, bypreventing an unauthorized person from executing a voice action such asdisarming the security system of a building.

In a general aspect, a method, which may be a computer-implementedmethod, includes obtaining (i) audio data representing a voice commandspoken by a speaker and (ii) a speaker identification result indicatingthat the voice command was spoken by the speaker, selecting a voiceaction based at least on a transcription of the audio data, selecting aservice provider corresponding to the selected voice action from among aplurality of different service providers, identifying one or more inputdata types that the selected service provider uses to performauthentication for the selected voice action, and providing, to theservice provider, (i) a request to perform the selected voice action and(i) one or more values that correspond to the identified one or moreinput data types. As noted, a “voice action” (or voice-initiated action)is an action that is initiated by a voice command (e.g., a speechutterance) of a user.

Other implementations of this and other aspects include correspondingsystems, apparatus, and computer programs, configured to perform theactions of the methods, encoded on computer storage devices. A system ofone or more computers can be so configured by virtue of software,firmware, hardware, or a combination of them installed on the systemthat in operation cause the system to perform the actions. One or morecomputer programs can be so configured by virtue of having instructionsthat, when executed by data processing apparatus, cause the apparatus toperform the actions. In another aspect a computer storage medium, whichmay be a non-transitory computer storage medium, stores a computerprogram, the program comprising instructions that when executed by oneor more computers cause the one or more computers to perform operationscomprising obtaining (i) audio data representing a voice command spokenby a speaker and (ii) a speaker identification result indicating thatthe voice command was spoken by the speaker; selecting a voice actionbased at least on a transcription of the audio data; selecting a serviceprovider corresponding to the selected voice action from among aplurality of different service providers; identifying one or more inputdata types that the selected service provider uses to performauthentication for the selected voice action; and providing, to theservice provider, (i) a request to perform the selected voice action and(i) one or more values that correspond to the identified one or moreinput data types.

Implementations may include one or more of the following features. Forinstance, in certain aspects obtaining (i) audio data representing avoice command spoken by a speaker and (ii) a speaker identificationresult indicating that the voice command was spoken by the speaker mayinclude obtaining the audio data representing the voice command spokenby the speaker, obtaining a voiceprint for the speaker, determining thatthe voiceprint for the speaker matches the audio data representing thevoice command spoken by the speaker, and in response to determining thatthe voiceprint for the speaker matches the audio data representing thevoice command spoken by the speaker, generating the speakeridentification result indicating that the voice command was spoken bythe speaker.

In some aspects, selecting a voice action based at least on atranscription of the audio data includes obtaining a set of voiceactions, where each voice action identifies one or more terms thatcorrespond to that voice action, determining that one or more terms inthe transcription match the one or more terms that correspond to thevoice action, and in response to determining that the one or more termsin the transcription match the one or more terms that correspond to thevoice action, selecting the voice action from among the set of voiceactions.

In some implementations, selecting a service provider corresponding tothe selected voice action from among a plurality of different serviceproviders includes obtaining a mapping of voice actions to the pluralityof service providers, where for each voice action the mapping describesa service provider that can perform the voice action, determining thatthe mapping of voice actions indicates that the service provider canperform the selected voice action, and in response to determining thatthe mapping of voice actions indicates that the service provider canperform the selected voice action, selecting the service provider.

In certain aspects, identifying one or more input data types that theselected service provider uses to perform authentication for theselected voice action includes providing, to the selected serviceprovider, a request for an identification of one or more input datatypes that the selected service provider uses to perform authenticationfor the selected voice action, receiving, from the selected serviceprovider, a response to the request for the identification, and

identifying the one or more input data types that the selected serviceprovider uses to perform authentication for the selected voice actionfrom the response to the request for the identification.

In some aspects, actions include generating the transcription of theaudio data using an automated speech recognizer. In someimplementations, actions include receiving, from the service provider,an indication that the selected voice action has been performed. Incertain aspects, actions include receiving, from the service provider,an indication that additional authentication is needed to perform theselected voice action and in response to receiving, from the serviceprovider, the indication that additional authentication is needed toperform the selected voice action, providing a request for additionalauthentication. In some aspects, identifying one or more input datatypes that the selected service provider uses to perform authenticationfor the selected voice action includes identifying that the selectedservice provider uses one or more of an input data type that indicateswhether the speaker's mobile computing device has been on a body sincethe mobile computing device was last unlocked, an input data type thatindicates whether a speaker's mobile computing device is in short-rangecommunication with a particular device, an input data type thatindicates whether a speaker's mobile computing device is within aparticular geographic area, or an input data type that indicates whethera speaker's face is in a view of a device.

In some aspects, before providing, to the service provider, (i) therequest to perform the selected voice action and (ii) the one or morevalues that correspond to the identified one or more input data types,there may be a preliminary determination whether the one or more valuessatisfy one or more known minimum requirements of the service provider.If the determination is positive the request is sent to the serviceprovider, but if the determination is negative the request is not sentto the service provider.

The details of one or more embodiments of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other potential features, aspects, and advantages ofthe subject matter will become apparent from the description, thedrawings, and the claims. It will be appreciated that aspects andimplementations can be combined, and that features described in thecontext of one aspect or implementation can be implemented in thecontext of other aspects or implementations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram that illustrates an example interaction with asystem for securely executing voice actions.

FIG. 2 is a block diagram of an example system for securely executingvoice actions.

FIG. 3 is a block diagram of an example voice action server for securelyexecuting voice actions.

FIG. 4 is a flow diagram that illustrates an example of a process forsecurely executing voice actions.

FIG. 5 is a diagram of examples of computing devices.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

FIG. 1 is a block diagram that illustrates an example interaction 100with a system for securely executing voice actions. The interaction 100is between a user 110 and the system 120. In the example, the system 120includes a television that includes a microphone that can listen tospeech from the user 110 and a speaker that can output synthesizedspeech to the user 110. In other examples, the system 120 may include anadditional or alternate device that can perform voice actions. As shownin the example, the system 120 enforces different levels of securityrequirements for voice commands depending on the nature of the voicecommand and context of the voice command, and also uses voiceidentification as part of a determination whether to perform a voiceaction.

As illustrated, the user 110 initially says “Change temperature to 70degrees.” The system 120 receives the utterance from the user 110,determines that the current temperature is 68 degrees and, in response,determines that changing the temperature to 70 degrees is a small changethat doesn't require any authentication. The system 120 then changes thetemperature setting of the home to 70 degrees and outputs synthesizedspeech of “Temperature changed from 68 degrees to 70 degrees.”

Continuing the example, the user 110 later says “Change temperature to80 degrees.” The system 120 receives the utterance from the user 110,determines that the current temperature is 70 degrees and, in response,determines that changing the temperature to 80 degrees is a large changethat requires a low level of authentication. The system 120 thenidentifies the speaker as “John Doe” by matching a stored voiceprint for“John Doe” with the utterance, and determines that a mobile computingdevice registered with “John Doe” is at home. Because the system 120determines that the voice identification and/or presence of the mobilecomputing device satisfy the “low” level of authentication requirements,the system 120 changes the temperature setting of the home to 80 degreesand outputs synthesized speech of “Temperature changed from 70 degreesto 80 degrees.” A stored voiceprint may indicate a sound of a user'svoice including one or more of pitch, speed, tone, pronunciation,accent, modulation, or other aspects.

The user 110 later says “Disarm security system.” The system 120receives the utterance from the user 110, determines that disarming thesecurity system requires a high level of authentication, which hasgreater security requirements than the other commands shown in FIG. 2.To determine whether to carry out the command, the system 120 identifiesthe speaker as “John Doe” from matching a stored voiceprint for “JohnDoe” with the utterance, determines that a mobile computing deviceregistered with “John Doe” is at home, and determines that a mobilecomputing device registered with “John Doe” has been on a person's bodysince it was last unlocked. The system 120 determines that togetherthese factors satisfy the “high” level of authentication, and, inresponse, disarms the security system and outputs synthesized speech of“security system disarmed.”

In general, a device can determine if it has been continuously worn by auser since it was unlocked using one or more sensors. For example, adevice may include a capacitive sensor, a resistive sensor, an opticalsensor, a temperature sensor, a pressure sensor, an EKG sensor, or othersensor for detecting the presence of and/or the characteristics of auser's body. The sensor may generate data at an interval (e.g., every100 ms, every second, or every 10 seconds, etc.), and the data can beindicative of whether the device is in contact with, or within apredetermined distance of, a user's body. As an example, a watch mayinclude a sensor that faces toward or contacts a wearer's wrist. Thesensor may detect contact with the user's skin, or lack thereof, basedon detecting capacitance. In addition, or as an alternative, the sensormay measure light detected at the back of the watch facing the user'swrist, for example, to show that the back of the watch remains covered,or to measure light reflection or absorption from LEDs of the devicethat direct light toward the users wrist. Data from the sensors can betracked over time and compared with predetermined thresholds and rangesto determine whether the watch has been worn continuously since it wasunlocked. Similar techniques may be used to detect whether necklaces,hats, rings, and other wearable devices have been worn continuously overa period of time.

FIG. 2 is a block diagram of an example system 200 for securelyexecuting voice actions. In some implementations, the system 200 may bethe system 120 shown in FIG. 1. The system 200 for securely executingvoice actions may include a local device 210, a voice action server 220,a mobile computing device 230, and service providers 240A, 240B, 240C(collectively 240).

The local device 210 may be a device that includes a microphone that iswithin an audible hearing range of a user speaking a voice command. Forexample, the local device 210 may be a voice-action-enabled television,a countertop home voice automation device, or a home security systemwith voice automation functionality. A voice command may refer to speechthat triggers the system 200 to attempt to perform a voice action. Forexample, voice commands that request the voice action of disarming asecurity system may include “Disarm security system,” “Turn off securitysystem,” or “Security system to disarmed state.” A voice action mayrefer to an action that is triggered by speech. For example, a voiceaction of disarming a security system may refer to an action, that istriggered by speech: of disarming a security system.

The local device 210 may receive an utterance from a user and provideaudio data representing the utterance to the voice action server 220.Audio data may include Mel Frequency Cepstral Coefficients (MFCC) thatrepresent the utterance. For example, the local device 210 may use amicrophone to detect sounds including the user speaking “Disarm securitysystem,” and in response, provide audio data representing that utteranceto the voice action server 220. The local device 210 may additionally oralternatively receive information from the voice action server 220 toprovide to a user. For example, the local device 210 may receive audiodata for synthesized speech of “Security system disarmed” and thenoutput the synthesized speech through a speaker to the user.

The voice action server 220 may receive, from the local device 210,audio data representing an utterance, extract the utterance from thereceived data, and determine whether to perform a voice actioncorresponding to the utterance. For example, the voice action server 220may receive audio data representing the utterance “disarm securitysystem” and determine to perform a voice action for disarming a homesecurity system. The voice action server 220 also facilitatescommunication with the service providers 240 and in gathering contextualinformation that allow the service providers 240 to determine whetherthe security requirements for voice actions have been met. For example,the voice action server 220 can receive contextual information from thelocal device 210 and pass the information to the service providers 240.When additional information is needed from the user, or when errorsoccur, information can be transmitted between the user and the serviceproviders 240 through the voice action server 220.

In determining to perform a voice action, the voice action server 220may select a service provider to perform the voice action. Each of theservice providers 240 may be associated with particular actions or typesof actions that they handle, and the voice action server 220 may routeeach request to the appropriate service provider 240. For example, indetermining to perform a voice action of disarming a home securitysystem, the voice action server 220 may select service provider A 240Athat may be associated with a home security system. In another example,in response to determining to perform a voice action of making areservation at a restaurant, the voice action server 220 may selectservice provider B 240B that may be associated with a restaurantreservation management application or website.

The voice action server 220 may identify input data types that theselected service provider uses to perform authentication and values forthose data types. Different service providers 240 may use differenttypes of input data to determine whether appropriate authentication orsecurity requirements have been met. Similarly, different voice actionssupported by a single service provider may require different types ofinput data. The voice action server 220 may format each voice actionrequest to include the data needed to assess the security requirementsfor the particular voice action being requested, and for the particularservice provider to which the voice action request is sent. For example,the voice action server 220 may determine that the service provider A240A uses a data type of voice match confidence, a data typecorresponding to geographical location of a user's mobile computingdevice, and a data type corresponding to a status of a user's mobilecomputing device being on a person's body since last unlock. Then, thevoice action server 220 determines values for these data types, e.g.,data indicating that there's a 90% voice match confidence, that theuser's mobile computing device is within a particular geographic area,and that the user's mobile computing device was on a person's body sinceit was last unlocked. In another example, the voice action server 220may determine that the service provider B 240B uses a voice matchconfidence and a status about a mobile computing device being on aperson's body since last unlock, and then determine values indicatingthat there's a 80% voice match confidence and the user's mobilecomputing device was on a person's body since it was last unlocked.

The input data types may represent contextual signals that can be usedto authenticate the user without requesting the user provide explicitauthentication information. Input data types may include one or more ofan input data type that indicates whether the speakers mobile computingdevice has been on a body since the mobile computing device was lastunlocked, an input data type that indicates whether a speakers mobilecomputing device is in short-range communication with a particulardevice, an input data type that indicates whether a speaker's mobilecomputing device is within a particular geographic area, or an inputdata type that indicates whether a speaker's face is in a view of adevice.

For example, a value for a voice match confidence may be determinedbased on using the audio data representing a voice command withoutrequesting the user provide additional speech for authenticationpurposes. In another example, a value for users mobile computing devicebeing in physical proximity may be determined based on determiningwhether a mobile computing device, of a user identified from the audiodata representing a voice command, is within a geographical area withouthaving the user provide additional information. In yet another example,the voice action server 220 may receive an image of a speaker from anetworked camera with a view of the local device 210 and for an inputdata type indicating whether a speakers face is verified by thenetworked camera determine a value that indicates whether the speakersface is verified.

The voice action server 220 may determine the values for the identifiedinput data types based on the mobile computing device 230 of the user.For example, the voice action server 220 may determine that a usersmobile computing device 230 is at home, e.g., that a location of thedevice 230 coincides with a location the user designated as the usershome, or the computing device 230 is in short-range communication withthe device 210 known to be located in the user's home. The voice actionserver 220 may then determine a value indicating that the users mobilecomputing device 230 is at home, and provide the value to a serviceprovider when the service provider is configured to receive data of thattype.

In some implementations, the voice action server 220 may determine anidentity of the user from the audio data, identify the mobile computingdevice 230 of the user, determine a status of the mobile computingdevice, and then determine the values for the identified input datatypes from the status of the mobile computing device. For example: thevoice action server 220 may determine that a voice command is from “JohnDoe” based on the voice in the voice command matching a stored voiceprint for “John Doe,” determine a device identifier stored for themobile computing device 230 used by “John Doe,” request information fromthe device 230 corresponding to the device identifier, receive therequested information from the device 230, and generate values using theinformation from the device 230. In another example, the voice actionserver 220 may determine that a voice command is from “John Doe” basedon the voice in the voice command matching a stored voice print for“John Doe,” determine a device identifier stored for the mobilecomputing device 230 used by “John Doe,” identify information alreadystored by the voice action server 220 corresponding to the deviceidentifier, and generate values using the identified already storedinformation.

The information from the device 230 may include one or more of, alocation of the device 230 based on a GPS sensor in the device 230:other devices with which the device 230 is in short range wirelesscommunication, whether the device 230 has been on a person's body sincethe device 230 was last unlocked, an image of a current view of thedevice 230, or some other information.

In another example, the voice action server 220 may determine that avoice command is from “John Doe” based on the voice in the voice commandmatching a stored voice print for “John Doe,” determine a deviceidentifier stored for the mobile computing device 230 used by “JohnDoe,” request information from other devices about the device 230corresponding to the device identifier, receive the requestedinformation from the other devices, and generate values using theinformation from the other devices. The information from the device 230may include one or more of, an indication that the other device is inshort range wireless communication with the device 230 or the device 230was detected within a geographic area by the other device.

In some implementations, the voice action server 220 additionally oralternatively receives information from the local device 210 that can beused to generate values for input data types. The local device 210 mayprovide the information with the audio data representing the utteranceof a voice command or provide the information in response to the voiceaction server 220 requesting information from the local device 210.

The voice action server 220 may provide the selected service provider arequest to perform a voice action and values for the identified inputdata types that the selected service provider uses to performauthentication. For example, the voice action server 220 may provideservice provider A 240A a request to disarm a security system and valuesindicating (i) that there's a 80% voice match confidence that the useris “John Doe” and (ii) that the mobile computing device of “John Doe” iswithin a particular geographic area and was on a person's body since itwas last unlocked.

The voice action server 220 may provide the selected service providervalues for the identified input data types, as the service providers mayhave additional information or rules for use in determining anappropriate level of authentication that the voice action server 220 maynot have. For example, the level of authentication for changing a hometemperature may be dependent on the amount of change, e.g., smallchanges may need no or little authentication but large changes that mayresult in substantial costs may require increasingly highauthentication, and voice action server 220 may not know a currenttemperature setting of a home that the service provider knows.Accordingly, the arrangement may enable flexibility for serviceproviders to determine rules for authentication and may enable securityby limiting the information provided to the voice action server 220.Furthermore, in this implementation the speaker is not required toprovide explicit authentication information (such as providing anauthorization PIN code) so that the method is convenient for thespeaker.

In response to providing the request and values to the selected serviceprovider, the voice action server 220 may receive an indication that theselected voice action was performed. For example, the voice actionserver 220 may receive an indication of completed from service providerA 430A. In response to the indication that the selected voice action wasperformed, the voice action server 220 may provide an indication to thelocal device 210 that the voice action was performed.

Additionally or alternatively, in response to providing the request andvalues to the selected service provider, the voice action server 220 mayreceive an indication that additional authentication is needed toperform the selected voice action. For example, the voice action server220 may receive, from the service provider A 430A, an indication ofadditional authentication needed by the service provider A 430A.

In response to the indication that additional authentication is needed,the voice action server 220 may provide an indication to the localdevice 210 that the voice action was not performed because additionalauthentication was needed. In some implementations, the indication fromthe selected server provider may indicate an input data type for theadditional authentication needed and the voice action server 220 mayprovide a request to the local device 210 for the user to provideinformation for the input data type needed for the additionalauthentication. In some implementations, the additional authenticationmay include request may be an explicit authorization code, a password,additional voice verification phrases, or that the user agree to usingadditional types of contextual information for authorization in thefuture.

In some implementations, the voice action server 220 may additionally oralternatively perform some authentication. For example, the voice actionserver 220 may obtain minimum authentication requirements for particularservice providers or particular voice actions performed by particularservice providers, and may make an initial determination whether thoseminimum authentication requirements are satisfied. In the example, ifthe minimum requirements are not satisfied, the voice action server 220may not send the request to the selected service provider but insteadindicate to the user that additional authentication information isnecessary. This reduces the time taken to authenticate the user, byeliminating the delay that would otherwise be caused by the voice actionserver sending the request to the selected service provider andreceiving notification from the service provider that it had notaccepted the request before the user was advised that additionalauthentication information is necessary.

The service providers 240 may include on or more of a device, e.g., athermostat or a home security system, an application, e.g., a calendarapplication or a voice dialing application, or a website, e.g., anonline banking or online shopping website, or other entity, registeredto perform certain actions or types of actions. As discussed above, theservice providers 240 may have information that is unavailable to thevoice action server 220 and may make an assessment of whether a voiceaction can be performed based on the information from the server usedfor authentication and from the information that is unavailable to thevoice action server 220 but available to the service providers 240.

In some implementations, a voiceprint for the speaker may not beavailable and the system 200 may use input data types other than thosebased on voice verification for authentication. For example, the system200 may use facial recognition only instead of facial recognition andvoice verification.

In some implementations, the mobile computing device 230 may performvoice verification. For example, the mobile computing device 230 and thelocal device 210 both detect the same utterance. In the example, themobile computing device 230 identifies the speaker and determines avoice match confidence, and then provides the identification and voicematch confidence for the voice action server 220. The voice actionserver 220 then uses the identification and voice match confidence fromthe mobile computing device 230 instead of identifying the speaker anddetermining a voice match confidence. In another example, the mobilecomputing device 230 identifies the speaker and determines a voice matchconfidence, and then provides the identification and voice matchconfidence for the local device 210 to provide to the voice actionserver 220 along with the audio data representing the voice command. Inyet another example, the local device 210 provides the audio datarepresenting the voice command to the mobile computing device 230 toidentify the speaker and determine a voice match confidence, and themobile computing device 230 then provides the identification of thespeaker and the voice match confidence to either the local device 210 toprovide the voice action server 220 or directly to the voice actionserver 220.

Different configurations of the system 200 may be used wherefunctionality of the local device 210, the voice action server 220, themobile computing device 230, and the service providers 240A, 240B, 240C(collectively 240) may be combined, further separated, distributed, orinterchanged. The system 200 may be implemented in a single device ordistributed across multiple devices.

Speaker verification can be performed by any of various devices in thesystem 200. For example, the local device 210 may identify a speaker ofa command, the voice action server 220 may identify the speaker of thecommand, or both may independently or cooperatively perform speakeridentification. The identity of a speaker may be determined using thespeech of the command itself, using a hotword or attention word that isspoken immediately before the command, or using other speech before orafter the command.

FIG. 3 is a block diagram of an example voice action server 300 forsecurely executing voice actions. In some implementations, the server300 may be the voice action server 220 shown in FIG. 2. In otherimplementations, the server 300 may be another voice action server.

The voice action server 300 may include a conversation manager 310, anautomated speech recognizer 320, a provider selection engine 330, avoice action database 332, a speaker identifier 340, a speakervoiceprint database 342, an input data value determinator 350, and aprovider interface 360.

The conversation manager 310 may manage a conversation with a user. Forexample, the conversation manager 310 may receive audio datarepresenting speech of users and provide synthesized speech in responseto the speech from users. The conversation manager 310 may receive audiodata from a local device and provide the audio data to the automatedspeech recognizer 320 and the speaker identifier 340. For example, theconversation manager 310 may receive audio data representing “Changetemperature to 80 degrees” and provide the audio data to the automatedspeech recognizer 320 and the speaker identifier 340. The conversationmanager 310 may receive indications from the provider interface 360whether a voice command was performed and then provide an indication toa local device. For example, the conversation manager 310 may receive anindication that a voice command for changing a temperature was performedto change the temperature from 70 degrees to 80 degrees and, inresponse, generate synthesized speech of “Temperature changed from 70degrees to 80 degrees”.

The automated speech recognizer 320 may receive audio data representinga voice command and generate a transcription of the audio data. Forexample, the automated speech recognizer 320 may receive audio datarepresenting the voice command “Change temperature to 80 degrees” and,in response, generate a transcription of “Change temperature to 80degrees.” The automated speech recognizer 320 may provide the generatedtranscription to the provider selection engine 330. For example, theautomated speech recognizer 320 may provide the transcription “Changetemperature to 80 degrees” to the provider selection engine 330.

The provider selection engine 330 may receive a transcription and selecta voice action based on the transcription. For example, the providerselection engine 330 may receive the transcription “Change temperatureto 80 degrees” and, in response, selection a voice action of “Changetemperature” based on the transcription.

In selecting the voice action, the provider selection engine 330 mayaccess data that indicates a set of voice actions from a voice actiondatabase 332, where each voice action identifies one or more terms thatcorrespond to that voice action. For example, the voice action database332 may indicate a set of voice actions including a voice action of“Change temperature” that is associated with the terms “Changetemperature,” “Temperature change,” “Set temperature,” or other terms.Another voice action indicated could be the action of “Disarm securitysystem” that is associated with the terms “Disarm security system,”“Unarm security system,” “Set security system to disarmed,” or otherterms. The provider selection engine 330 may determine that one or moreterms in the transcription match one or more terms that correspond to avoice action. For example, the provider selection engine 330 maydetermine that the transcription “Change temperature to 80 degrees”includes the terms “Change temperature.” In response to determining thatthe one or more terms in the transcription match the one or more termsthat correspond to the voice action, the provider selection engine 330may select a voice action from among the set of voice actions. Forexample, in response to determining that the transcription “Changetemperature to 80 degrees” includes the terms “Change temperature,” theprovider selection engine 330 may select the voice action “Changetemperature.”

The provider selection engine 330 may provide an indication of theselected voice action to the provider interface 360. For example, theprovider selection engine 330 may provide the provider interface 360 anindication that the voice action of “Change temperature” was selected.

The speaker identifier 340 may obtain the audio data representing avoice command spoken by a speaker and generate a speaker identificationresult that indicates that the voice command was spoken by the speaker.For example, the speaker identifier 340 may obtain the audio datarepresenting the voice command “Change temperature to 80 degrees” spokenby “John Doe” and generate a speaker identification results thatindicates that the voice command was spoken by “John Doe.”

The speaker identifier 340 may generate the speaker identificationresult by matching the audio data representing a voice command, or ahotword preceding the voice command, with a voiceprint for a user. Forexample, the speaker identifier 340 may generate the speakeridentification result that indicates that “John Doe” spoke the voicecommand based on determining that the audio data for the voice commandmatches a stored voiceprint for “John Doe.” The speaker identifier 340may obtain the voiceprint for the user among a set of voiceprints storedin the speaker voiceprint database 342.

In some implementations, the speaker identifier 340 may determine amatch confidence that represents a degree of match between thevoiceprint for a user and the audio data that represents the voicecommand and include the match confidence in the speaker identificationresult. For example, the speaker identifier 340 may determine a matchconfidence of 80% and include an indication of a match confidence of 80%in the speaker identification result.

In some implementations, the speaker identifier 340 may only identify asingle user in the speaker identification result. For example, thespeaker identifier 340 may determine the user with the match confidencethat indicates the highest degree of match and identify that user in thespeaker identification result and the match confidence for that speaker.In other implementations, the speaker identifier 340 may identifymultiple users in the speaker identification result. For example, thespeaker identifier 340 may identify the users with match confidencesthat satisfy a match confidence threshold, e.g., 50%, 60%, 75%, or someother match confidence, and identify those users in the speakeridentification result and their corresponding match confidences. Inanother example, the speaker identifier 340 may identify the users withmatch confidences indicating the two, three, or some other number,highest degrees of match and identify those users in the speakeridentification result and their corresponding match confidences. Thespeaker identifier 340 may provide the speaker identification result tothe input data value determinator 350.

In some implementations, a local device, such as a device in a user'shome or workplace, may perform speaker verification instead of, or inaddition to, the speaker identifier 340. For example, the local devicemay store information derived from speech samples the user provided atenrollment, allowing the local device to determine whether a speaker'svoice matches characteristics observed during enrollment. The localdevice may provide, to the server 300, a speaker verification confidencescore and/or a classification result of whether the speaker is likely anauthorized user. In addition to speaker verification information, thelocal device may provide a variety of other contextual information.Generally, the local device may provide as much contextual informationas is available and provide it automatically with the voice command. Theserver 300 then determines which information is needed, and which formatis appropriate, to pass to service providers in voice action requests.

The input data value determinator 350 may determine values for inputdata types used by service providers based on the identified user. Forexample, the input data value determinator 350 may determine a binaryvalue indicating whether a mobile computing device of a user identifiedas speaking a voice command is within the user's home. The input datatypes may include one or more of whether a mobile computing device of auser is in a trusted area based on a GPS sensor in the device 230,whether a mobile computing device of a user is in wireless communicationwith a trusted device, whether the device 230 has been worn on aperson's body since the device 230 was last unlocked, whether the userin a current view of the device 230 matches a stored face for the user,or some other input value data types. A trusted area may be an area inwhich the user has designated that the user would like to provide voicecommands. A trusted device may be a device that the user has designatedthat the user would like to provide commands when the mobile computingdevice of the user is in communication with the trusted device.

Similar to the manner described above for the voice action server 220,the input data value determinator 350 may identify a device identifierstored for the mobile computing device used by the identified user,request information from the identified mobile computing device, receivethe requested information from the identified mobile computing device,and then generate values for the input data types based on theinformation. As described above, the input data value determinator 350may alternatively identify a device identifier stored for the mobilecomputing device used by the identified user, request information fromother devices regarding the identified mobile computing device, receivethe requested information from the other devices, and then generatevalues for the input data types based on the information.

The input data value determinator 350 may provide the determined datatypes to the provider interface 360. For example, the input data valuedeterminator 350 may provide the provider interface 360 an indicationthat a users mobile computing device is not in a trusted area and thatthe user's mobile computing device has been on a person's body since itwas last unlocked.

The provider interface 360 may receive an indication of a selectedservice provider and a selected voice action from the provider selectionengine 330, and may receive values of input data types from the inputdata value determinator 350 and, in response, provide a request toperform the selected voice action to the selected service provider andone or more values of the input data types. For example, the providerinterface 360 may receive an indication of a selected service providerfor heating, ventilating, and air conditioning (HVAC) control and anindication of a selected voice action of changing temperature, as wellas values for input data types that indicate that (i) that there's a 80%voice match confidence that the user is “John Doe” and (ii) that themobile computing device of “John Doe” is within a particular geographicarea and (iii) that the mobile computing was on a person's body since itwas last unlocked. With this information, the provider interface 360provides the selected service provider an indication of a selected voiceaction of changing temperature, and provides values that indicate that(i) that there's a 80% voice match confidence that the user is “JohnDoe” and (ii) that the mobile computing device of “John Doe” is within aparticular geographic area. The provider interface 360 may omitproviding a value that indicates that the mobile computing device was ona person's body since it was last unlocked as the selected serviceprovider may not use that input data type.

The provider interface 360 may provide one or more values thatcorrespond to the identified one or more input data types based ondetermining a subset of the input data types that the selected serviceprovider uses to perform authentication for a selected voice action. Forexample, the provider interface 360 may provide values indicating voicematch confidence and whether a mobile computing device of that matcheduser is in a particular geographic area based on determining that forthe selected voice action of changing temperature the selected serviceprovider for HVAC control uses those input data types forauthentication. Different contextual information may be provided,depending on which provider is selected to handle the voice actionrequest. In another example, if the HVAC control system uses statusinformation about a mobile computing device, the provider interface 360may additionally provide a value indicating whether the mobile computingdevice was on a person's body since it was last unlocked. In yet anotherexample, the provider interface 360 may provide values of input datatypes of voice match confidence and whether a face in a current view ofa camera of the mobile computing device matches the voice matched userbased on determining that for the selected voice action of changingtemperature another, different selected service provider for HVACcontrol uses those input data types for authentication.

The provider interface 360 may receiver a response back from a serviceprovider indicating whether the voice action was performed or whetheradditional information for authentication is needed. For example, theprovider interface 360 may receive an indication from a selected serviceprovider for HVAC control that the voice action for changing temperaturewas completed. In another example, the provider interface 360 mayreceive an indication from a selected service provider for HVAC controlthat the voice action for changing temperature was not completed andthat a specific additional type of authentication information is needed.The provider interface 360 may provide the indication to theconversation manager 310 and the conversation manager 310 may providethe indication to the user, as discussed above.

Different configurations of the server 300 may be used wherefunctionality of the conversation manager 310, the automated speechrecognizer 320, the provider selection engine 330, the voice actiondatabase 332, the speaker identifier 340, the speaker voiceprintdatabase 342, the input data value determinator 350, and the providerinterface 360 may be combined, further separated: distributed, orinterchanged. For example, the provider interface 360 may perform thefunctions of the input data value determinator 350 to determine just thevalues for the input data types used by a selected service provider forauthentication for a selected voice action. The system 200 may beimplemented in a single device or distributed across multiple devices.

FIG. 4 is a flow diagram that illustrates an example of a process forsecurely executing voice actions. The operations of the process 400 maybe performed by one or more computing systems, such as the server 300 ofFIG. 3.

Audio data representing a voice command and a speaker identification isreceived (410). For example, the conversation manager 310 may receiveaudio data representing “Jane Doe” saying “Disarm security system.”Receiving the audio data and a speaker identification may includeobtaining audio data representing a voice command spoken by a speaker,obtaining a voiceprint for the speaker, determining that the voiceprintfor the speaker matches the audio data representing the voice commandspoken by the speaker, and, in response to determining that thevoiceprint for the speaker matches the audio data representing the voicecommand spoken by the speaker, generating the speaker identificationresult indicating that the voice command was spoken by the speaker.

A voice action may be selected (420). For example, the automated speechrecognizer 320 may generate the transcription “Disarm security system”and provide that transcription to the provider selection engine 330which may determine that those terms match up with a voice action ofdisarming a security system that is associated with the terms “Disarmsecurity system.” Selecting the voice action may include obtaining a setof voice actions, where each voice action identifies one or more termsthat correspond to that voice action, determining that one or more termsin the transcription match the one or more terms that correspond to thevoice action, and, in response to determining that the one or more termsin the transcription match the one or more terms that correspond to thevoice action, selecting the voice action from among the set of voiceactions.

A service provider corresponding to the voice action may be selected(430). For example, the provider selection engine 330 may determine thata service provider for a home security system can perform the voiceaction of disarming a security system and, in response, select theservice provider for a home security system. Selecting the serviceprovider corresponding to the voice action may include obtaining amapping of voice actions to the plurality of service providers, wherefor each voice action the mapping describes a service provider that canperform the voice action, determining that the mapping of voice actionsindicates that the service provider can perform the selected voiceaction, and in response to determining that the mapping of voice actionsindicates that the service provider can perform the selected voiceaction, selecting the service provider.

Input data types the selected service provider uses to performauthentication may be identified (440). For example, the providerinterface 360 may identify that the selected service provider for a homesecurity system uses the input data types of voice match confidence andwhether a user's mobile computing device is connected to the home'sWi-Fi network for authentication the voice action of disarming asecurity system. Identifying input data types may include providing, tothe selected service provider, a request for an identification of one ormore input data types that the selected service provider uses to performauthentication for the selected voice action, receiving, from theselected service provider, a response to the request for theidentification, and identifying the one or more input data types thatthe selected service provider uses to perform authentication for theselected voice action from the response to the request for theidentification.

A request to perform the selected voice action and one or more valuesthat correspond to the identified input data types may be provided(450). For example: the provider interface 360 may provide the selectedservice provider for a home security system an indication that theselected voice action is disarming the home security system and valuesof a 90% voice match to “Jane Doe” and that Jane Doe's mobile computingdevice is connected to the home's Wi-Fi network.

FIG. 5 shows an example of a computing device 500 and a mobile computingdevice 550 that can be used to implement the techniques described here.The computing device may for example embody or implement the voiceaction server 300 of FIG. 3. The computing device 500 is intended torepresent various forms of digital computers, such as laptops, desktops,workstations, personal digital assistants, servers, blade servers,mainframes, and other appropriate computers. The mobile computing device550 is intended to represent various forms of mobile devices, such aspersonal digital assistants, cellular telephones, smart-phones, andother similar computing devices. The components shown here, theirconnections and relationships, and their functions, are meant to beexamples only, and are not meant to be limiting.

The computing device 500 includes a processor 502, a memory 504, astorage device 506, a high-speed interface 508 connecting to the memory504 and multiple high-speed expansion ports 510, and a low-speedinterface 512 connecting to a low-speed expansion port 514 and thestorage device 506. Each of the processor 502, the memory 504, thestorage device 506, the high-speed interface 508, the high-speedexpansion ports 510, and the low-speed interface 512, are interconnectedusing various busses, and may be mounted on a common motherboard or inother manners as appropriate. The processor 502 can process instructionsfor execution within the computing device 500, including instructionsstored in the memory 504 or on the storage device 506 to displaygraphical information for a graphical user interface (GUI) on anexternal input/output device, such as a display 516 coupled to thehigh-speed interface 508. In other implementations, multiple processorsand/or multiple buses may be used, as appropriate, along with multiplememories and types of memory. Also, multiple computing devices may beconnected, with each device providing portions of the necessaryoperations (e.g., as a server bank, a group of blade servers, or amulti-processor system).

The memory 504 stores information within the computing device 500. Insome implementations, the memory 504 is a volatile memory unit or units.In some implementations, the memory 504 is a non-volatile memory unit orunits. The memory 504 may also be another form of computer-readablemedium, such as a magnetic or optical disk.

The storage device 506 is capable of providing mass storage for thecomputing device 500. In some implementations, the storage device 506may be or contain a computer-readable medium, such as a floppy diskdevice, a hard disk device, an optical disk device, or a tape device, aflash memory or other similar solid state memory device, or an array ofdevices, including devices in a storage area network or otherconfigurations. Instructions can be stored in an information carrier.The instructions, when executed by one or more processing devices (forexample, processor 502), perform one or more methods, such as thosedescribed above. The instructions can also be stored by one or morestorage devices such as computer- or machine-readable mediums (forexample, the memory 504, the storage device 506, or memory on theprocessor 502).

The high-speed interface 508 manages bandwidth-intensive operations forthe computing device 500, while the low-speed interface 512 manageslower bandwidth-intensive operations. Such allocation of functions is anexample only. In some implementations, the high-speed interface 508 iscoupled to the memory 504, the display 516 (e.g., through a graphicsprocessor or accelerator), and to the high-speed expansion ports 510,which may accept various expansion cards (not shown). In theimplementation, the low-speed interface 512 is coupled to the storagedevice 506 and the low-speed expansion port 514. The low-speed expansionport 514, which may include various communication ports (e.g., USB,Bluetooth, Ethernet, wireless Ethernet) may be coupled to one or moreinput/output devices, such as a keyboard, a pointing device, a scanner,or a networking device such as a switch or router, e.g., through anetwork adapter.

The computing device 500 may be implemented in a number of differentforms, as shown in the figure. For example, it may be implemented as astandard server 520, or multiple times in a group of such servers. Inaddition, it may be implemented in a personal computer such as a laptopcomputer 522. It may also be implemented as part of a rack server system524. Alternatively, components from the computing device 500 may becombined with other components in a mobile device (not shown), such as amobile computing device 550. Each of such devices may contain one ormore of the computing device 500 and the mobile computing device 550,and an entire system may be made up of multiple computing devicescommunicating with each other.

The mobile computing device 550 includes a processor 552, a memory 564,an input/output device such as a display 554, a communication interface566, and a transceiver 568, among other components. The mobile computingdevice 550 may also be provided with a storage device, such as amicro-drive or other device, to provide additional storage. Each of theprocessor 552, the memory 564, the display 554, the communicationinterface 566, and the transceiver 568, are interconnected using variousbuses, and several of the components may be mounted on a commonmotherboard or in other manners as appropriate.

The processor 552 can execute instructions within the mobile computingdevice 550, including instructions stored in the memory 564. Theprocessor 552 may be implemented as a chipset of chips that includeseparate and multiple analog and digital processors. The processor 552may provide, for example, for coordination of the other components ofthe mobile computing device 550, such as control of user interfaces,applications run by the mobile computing device 550, and wirelesscommunication by the mobile computing device 550.

The processor 552 may communicate with a user through a controlinterface 558 and a display interface 556 coupled to the display 554.The display 554 may be, for example, a TFT (Thin-Film-Transistor LiquidCrystal Display) display or an OLED (Organic Light Emitting Diode)display, or other appropriate display technology. The display interface556 may comprise appropriate circuitry for driving the display 554 topresent graphical and other information to a user. The control interface558 may receive commands from a user and convert them for submission tothe processor 552. In addition, an external interface 562 may providecommunication with the processor 552, so as to enable near areacommunication of the mobile computing device 550 with other devices. Theexternal interface 562 may provide, for example, for wired communicationin some implementations, or for wireless communication in otherimplementations, and multiple interfaces may also be used.

The memory 564 stores information within the mobile computing device550. The memory 564 can be implemented as one or more of acomputer-readable medium or media, a volatile memory unit or units, or anon-volatile memory unit or units. An expansion memory 574 may also beprovided and connected to the mobile computing device 550 through anexpansion interface 572, which may include, for example, a SIMM (SingleIn Line Memory Module) card interface. The expansion memory 574 mayprovide extra storage space for the mobile computing device 550, or mayalso store applications or other information for the mobile computingdevice 550. Specifically, the expansion memory 574 may includeinstructions to carry out or supplement the processes described above,and may include secure information also. Thus, for example, theexpansion memory 574 may be provided as a security module for the mobilecomputing device 550, and may be programmed with instructions thatpermit secure use of the mobile computing device 550. In addition,secure applications may be provided via the SIMM cards, along withadditional information, such as placing identifying information on theSIMM card in a non-hackable manner.

The memory may include, for example, flash memory and/or NVRAM memory(non-volatile random access memory), as discussed below. In someimplementations, instructions are stored in an information carrier thatthe instructions, when executed by one or more processing devices (forexample, processor 552), perform one or more methods, such as thosedescribed above. The instructions can also be stored by one or morestorage devices, such as one or more computer- or machine-readablemediums (for example, the memory 564, the expansion memory 574, ormemory on the processor 552). In some implementations, the instructionscan be received in a propagated signal, for example, over thetransceiver 568 or the external interface 562.

The mobile computing device 550 may communicate wirelessly through thecommunication interface 566, which may include digital signal processingcircuitry where necessary. The communication interface 566 may providefor communications under various modes or protocols, such as GSM voicecalls (Global System for Mobile communications), SMS (Short MessageService), EMS (Enhanced Messaging Service), or MMS messaging (MultimediaMessaging Service), CDMA (code division multiple access), TDMA (timedivision multiple access), PDC (Personal Digital Cellular), NWCDMA(Wideband Code Division Multiple Access), CDMA2000, or GPRS (GeneralPacket Radio Service), among others. Such communication may occur, forexample, through the transceiver 568 using a radio-frequency. Inaddition, short-range communication may occur, such as using aBluetooth, WiFi, or other such transceiver (not shown). In addition, aGPS (Global Positioning System) receiver module 570 may provideadditional navigation- and location-related wireless data to the mobilecomputing device 550, which may be used as appropriate by applicationsrunning on the mobile computing device 550.

The mobile computing device 550 may also communicate audibly using anaudio codec 560, which may receive spoken information from a user andconvert it to usable digital information. The audio codec 560 maylikewise generate audible sound for a user, such as through a speaker,e.g., in a handset of the mobile computing device 550. Such sound mayinclude sound from voice telephone calls, may include recorded sound(e.g., voice messages, music files, etc.) and may also include soundgenerated by applications operating on the mobile computing device 550.

The mobile computing device 550 may be implemented in a number ofdifferent forms, as shown in the figure. For example, it may beimplemented as a cellular telephone 580. It may also be implemented aspart of a smart-phone 582, personal digital assistant, or other similarmobile device.

1. A method performed by a data processing apparatus, the methodcomprising: obtaining (i) audio data representing a voice command spokenby a speaker and (ii) contextual data from a client device of thespeaker, the contextual data comprising data representing contextualsignals that can authenticate the speaker without requiring the speakerto provide explicit authentication information; obtaining, based on theaudio data representing the voice command, a speaker identificationresult indicating that the voice command was spoken by the speaker;selecting a voice action based at least on a transcription of the audiodata; selecting a service provider corresponding to the selected voiceaction from among a plurality of different service providers;identifying one or more input data types that the selected serviceprovider uses to perform authentication for the selected voice action;obtaining, from the contextual data and without requiring the speaker toprovide explicit authentication information, one or more values thatcorrespond to the identified one or more input data types; andproviding, to the service provider, (i) a request to perform theselected voice action (ii) the speaker identification result and (iii)the one or more values that correspond to the identified one or moreinput data types.
 2. The method of claim 1, wherein obtaining audio datarepresenting a voice command spoken by a speaker and a speakeridentification result indicating that the voice command was spoken bythe speaker comprises: obtaining the audio data representing the voicecommand spoken by the speaker; obtaining a voiceprint for the speaker;determining that the voiceprint for the speaker matches the audio datarepresenting the voice command spoken by the speaker; and in response todetermining that the voiceprint for the speaker matches the audio datarepresenting the voice command spoken by the speaker, generating thespeaker identification result indicating that the voice command wasspoken by the speaker.
 3. The method of claim 1 or 2, wherein selectinga voice action based at least on a transcription of the audio datacomprises: obtaining a set of voice actions, wherein each voice actionidentifies one or more terms that correspond to that voice action;determining that one or more terms in the transcription match the one ormore terms that correspond to the voice action; and in response todetermining that the one or more terms in the transcription match theone or more terms that correspond to the voice action, selecting thevoice action from among the set of voice actions.
 4. The method of claim1, wherein selecting a service provider corresponding to the selectedvoice action from among a plurality of different service providerscomprises: obtaining a mapping of voice actions to the plurality ofservice providers, where for each voice action the mapping describes aservice provider that can perform the voice action; determining that themapping of voice actions indicates that the service provider can performthe selected voice action; and in response to determining that themapping of voice actions indicates that the service provider can performthe selected voice action, selecting the service provider.
 5. The methodof claim 1, comprising: generating the transcription of the audio datausing an automated speech recognizer.
 6. The method of claim 1,comprising: receiving, from the service provider, an indication thatadditional authentication is needed to perform the selected voiceaction; and in response to receiving, from the service provider, theindication that additional authentication is needed to perform theselected voice action, providing a request for additionalauthentication.
 7. The method of claim 1, comprising: receiving, fromthe service provider, an indication that the selected voice action hasbeen performed.
 8. The method of claim 1, wherein identifying one ormore input data types that the selected service provider uses to performauthentication for the selected voice action comprises: providing, tothe selected service provider, a request for an identification of one ormore input data types that the selected service provider uses to performauthentication for the selected voice action; receiving, from theselected service provider, a response to the request for theidentification; and identifying the one or more input data types thatthe selected service provider uses to perform authentication for theselected voice action from the response to the request for theidentification.
 9. The method of claim 1, wherein identifying one ormore input data types that the selected service provider uses to performauthentication for the selected voice action comprises: identifying thatthe selected service provider uses one or more of an input data typethat indicates whether the speaker's mobile computing device has been ona body since the mobile computing device was last unlocked, an inputdata type that indicates whether a speaker's mobile computing device isin short-range communication with a particular device, an input datatype that indicates whether a speaker's mobile computing device iswithin a particular geographic area, or an input data type thatindicates whether a speaker's face is in a view of a device.
 10. Asystem comprising: one or more computers and one or more storage devicesstoring instructions that are operable, when executed by the one or morecomputers, to cause the one or more computers to perform operationscomprising: obtaining (i) audio data representing a voice command spokenby a speaker and (ii) contextual data from a client device of thespeaker, the contextual data comprising data representing contextualsignals that can authenticate the speaker without requiring the speakerto provide explicit authentication information; obtaining, based on theaudio data representing the voice command, a speaker identificationresult indicating that the voice command was spoken by the speaker;selecting a voice action based at least on a transcription of the audiodata; selecting a service provider corresponding to the selected voiceaction from among a plurality of different service providers;identifying one or more input data types that the selected serviceprovider uses to perform authentication for the selected voice action;obtaining, by the data processing apparatus and from the contextual datawithout requiring the speaker to provide explicit authenticationinformation, one or more values that correspond to the identified one ormore input data types; and providing, to the service provider, (i) arequest to perform the selected voice action (ii) the speakeridentification result and (iii) the one or more values that correspondto the identified one or more input data types.
 11. The system of claim10, wherein obtaining (i) audio data representing a voice command spokenby a speaker and (ii) a speaker identification result indicating thatthe voice command was spoken by the speaker comprises: obtaining theaudio data representing the voice command spoken by the speaker;obtaining a voiceprint for the speaker; determining that the voiceprintfor the speaker matches the audio data representing the voice commandspoken by the speaker; and in response to determining that thevoiceprint for the speaker matches the audio data representing the voicecommand spoken by the speaker, generating the speaker identificationresult indicating that the voice command was spoken by the speaker. 12.The system of claim 10, wherein selecting a voice action based at leaston a transcription of the audio data comprises: obtaining a set of voiceactions, wherein each voice action identifies one or more terms thatcorrespond to that voice action; determining that one or more terms inthe transcription match the one or more terms that correspond to thevoice action; and in response to determining that the one or more termsin the transcription match the one or more terms that correspond to thevoice action, selecting the voice action from among the set of voiceactions.
 13. The system of claim 10, wherein selecting a serviceprovider corresponding to the selected voice action from among aplurality of different service providers comprises: obtaining a mappingof voice actions to the plurality of service providers, where for eachvoice action the mapping describes a service provider that can performthe voice action; determining that the mapping of voice actionsindicates that the service provider can perform the selected voiceaction; and in response to determining that the mapping of voice actionsindicates that the service provider can perform the selected voiceaction, selecting the service provider.
 14. The system of claim 10, theoperations comprising: generating the transcription of the audio datausing an automated speech recognizer.
 15. The system of claim 10, theoperations comprising: receiving, from the service provider, anindication that additional authentication is needed to perform theselected voice action; and in response to receiving, from the serviceprovider, the indication that additional authentication is needed toperform the selected voice action, providing a request for additionalauthentication.
 16. The system of claim 10, the operations comprising:receiving, from the service provider, an indication that the selectedvoice action has been performed.
 17. The system of claim 10, whereinidentifying one or more input data types that the selected serviceprovider uses to perform authentication for the selected voice actioncomprises: providing, to the selected service provider, a request for anidentification of one or more input data types that the selected serviceprovider uses to perform authentication for the selected voice action;receiving, from the selected service provider, a response to the requestfor the identification; and identifying the one or more input data typesthat the selected service provider uses to perform authentication forthe selected voice action from the response to the request for theidentification.
 18. The system of claim 10, wherein identifying one ormore input data types that the selected service provider uses to performauthentication for the selected voice action comprises: identifying thatthe selected service provider uses one or more of an input data typethat indicates whether the speaker's mobile computing device has been ona body since the mobile computing device was last unlocked, an inputdata type that indicates whether a speaker's mobile computing device isin short-range communication with a particular device, an input datatype that indicates whether a speaker's mobile computing device iswithin a particular geographic area, or an input data type thatindicates whether a speaker's face is in a view of a device. 19.(canceled)
 20. One or more computer-readable media storing instructionsthat, when executed by one or more computers, cause the one or morecomputers to perform operations comprising: obtaining (i) audio datarepresenting a voice command spoken by a speaker and (ii) contextualdata from a client device of the speaker, the contextual data comprisingdata representing contextual signals that can authenticate the speakerwithout requiring the speaker to provide explicit authenticationinformation; obtaining, based on the audio data representing the voicecommand, a speaker identification result indicating that the voicecommand was spoken by the speaker; selecting a voice action based atleast on a transcription of the audio data; selecting a service providercorresponding to the selected voice action from among a plurality ofdifferent service providers; identifying one or more input data typesthat the selected service provider uses to perform authentication forthe selected voice action; obtaining, by the data processing apparatusand from the contextual data without requiring the speaker to provideexplicit authentication information, one or more values that correspondto the identified one or more input data types; and providing, to theservice provider, (i) a request to perform the selected voice action(ii) the speaker identification result and (iii) the one or more valuesthat correspond to the identified one or more input data types.